Summary

shortest_path finds the minimum total cost route between nodes in a graph. In an unweighted_graph, bfs returns the shortest path by edge count. In a weighted_graph with non-negative weights, dijkstra with a priority_queue yields minimal path_cost. bellman_ford handles negative_weights and detects negative_cycles. Outputs often include distance and predecessor to rebuild a path from source to target. Common uses include routing, maps, and networks.